A white neo-Gothic castle perched on a rocky promontory above the sea, about 8 km north of the city centre. Built in the 1850s for Archduke Maximilian of Austria, it sits in a large park with formal gardens and direct views over the Gulf of Trieste. The park is free and open daily; the castle interior requires a ticket.
Worth visiting if you have time, but factor in the journey — it takes 20–30 minutes by bus from the city centre (bus 6 from Piazza Oberdan). Don't try to combine it with Risiera di San Sabba on the same day; pick one out-of-centre trip.